The MAGIX experiment aims to reach luminosities in the order of 1035cm-2s-1. Such high luminosities can be reached in two ways: Either by the appliance of a high intense beam and a low dense target, or the reverse case. Since MESA will recover the beam’s energy, only the former case can be applied, in order to keep the beam quality good enough after the interaction. Therefore the target material is a gas. To achieve that the beam is only interacting with the target gas and nothing else it is necessary to develop a target which doesn’t need any walls. Two target concepts are elaborated concidering the mentioned subjects.
The idea of the Jet Target is, to blast a high velocity gas through the vacuum in the scattering chamber perpendicular to the beamline, into a catcher, where the gas is then pumped away quickly. The gas will be accelerated in a Laval Nozzle, which allows to reach gas velocities faster than three times the sonic velocity. The goal is to construct the target in a way that the gas can be pumped away efficiently and the density of the jet is as high as possible.
Since for some measurements a spin polarized gas is necessary, a second target concept is required, since spin polarized gases are not stable at high pressures which are necessary for the jet target. Therefore a target which is basically a t-shaped tube made out of a thin mylar film. In the middle of the tube the gas will be injected. The beam will scatter with the gas on the way through the tube. After steaming out of the tube, the gas will be pumped away differentially. Since the target tub has a length of 300 mm, high luminosities can still be reached, even with lower dense gases.
Currently we are measuring the pumping power and the gas density of a jet target prototype.